1. Preheat oven to 350°F (175°C) and line a baking pan with parchment paper.

2. Whisk flour, cocoa powder, and salt in a medium bowl.

3. In a large bowl, stir melted butter, sugar, and vanilla until smooth.

4. Add eggs one at a time, mixing gently after each addition.

5. Fold dry mixture into wet mixture until just combined (don’t overmix).

6. Spread batter in pan and bake for 15–20 minutes, until edges set and center is slightly soft.

7. Cool brownies at room temperature for 1 hour, then chill for another hour before cutting.

8. For ganache: warm cream until steaming, pour over chopped semi-sweet chocolate, let sit 10 minutes, then stir smooth.

9. Melt white chocolate and transfer to a piping bag with a fine tip.

10. Spread ganache over each brownie, pipe a spiral of white chocolate, then drag a toothpick from center outward to form spiderwebs.

11. Let brownies set until firm before serving.